Arrhythmias in Hemodialysis Patients

Unstable Rhythms

Acute unstable or life-threatening rhythms, defined as heart rhythms associated with chest pain or evidence of circulatory insufficiency (e.g., frank shock, hypotension, impaired mentation), should be managed as per current ACLS guidelines. As a general rule, the dialysis procedure should be stopped unless a clear metabolic precipitant correctable by dialysis is present (e.g., hyperkalemia induced heart block). Intravenous access via the fistula or central line should be maintained. Because a thorough discussion of ACLS procedures is beyond the scope of this chapter, the reader is encouraged to download the latest edition of the ACLS recommendations (see Recommended Reading). Any additional considerations in hemodialysis patients are discussed under specific rhythm disturbances.

Avoiding Arrhythmogenic Triggers

Avoidance of arrhythmogenic stimuli during dialysis may be helpful, particularly in patients in whom dialysis reliably precipitates arrhythmias. Measures such as strict control of interdialytic fluid gain and potassium intake may decrease the need for aggressive ultrafiltration and low potassium dialysate. Substitution of normal instead of the usually elevated calcium bath may be helpful. Discontinuation of arrhythmogenic drugs (e.g., cardiac glycosides) should be seriously considered. Conversion to an alternative dialysis modality, such as peritoneal dialysis, short daily hemodialysis, or long hours of nocturnal hemodialysis, can be tried if other measures fail.

Treatment of Underlying Cardiac Disease

Aggressive medical and surgical therapy of underlying cardiac disease has been shown to prolong life and decrease morbidity in the general population. In contrast, with few exceptions, specific antiarrhythmic therapy does not prolong life and may increase mortality in patients with heart disease. In hemodialysis patients with arrhythmias, a search for an aggressive treatment of ischemic heart disease and left ventricular dysfunction is probably more important than antiarrhythmic therapy. Appropriate indications for established life-saving therapies such as aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and coronary revascularization are discussed elsewhere.

Ventricular Ectopy

Ventricular ectopic beats (also called ventricular premature contractions) are a common rhythm disturbance in dialysis. They may be precipitated or exacerbated by acute changes in volume and ECF composition. Minimizing these alterations may reduce or eliminate the ectopy ( Table 45.1 ). Medications should be reviewed to identify and stop proarrhythmia medications (e.g., domperidone). Blood chemistry should be reviewed to identify and correct derangements in calcium, potassium, and magnesium.

Complex ventricular ectopy is usually associated with underlying structural heart disease. Underlying cardiac disease should be aggressively sought and treated. With a cardiac history, electrocardiogram (ECG), echocardiogram, and cardiac perfusion scan are reasonable investigations to request in this regard. Referral to cardiology is indicated if significant cardiac disease is identified since treatment (e.g., coronary revascularization) will typically improve symptoms. In addition, cardiology referral is also indicated in patients with persistent ectopy despite review and optimization of dialysis prescription and medications, or if ectopy is complex or associated with persistent symptoms. Further therapeutic options for symptomatic patients or patients with frequent ectopic rhythms may include catheter ablation of an ectopic focus and consideration of implantable cardioverter defibrillator (ICD) in patients meeting ICD criteria.